High-speed blueprinting machine



Oct. 19, 1943. H. J. BRUNK HIGH SPEED BLUE PRINTING MACHINE Filed May 4, 1940 4 Sheets-Sheet 1 INVENTOR. o cc/Tfil "wut BY I I m. WW WTTORNEYS NTOR. J C

H. J. BRUNK 4 Sheets-Sheet 2 Oct. 19, 1943.

HIGH SPEED BLUE PRINTING MACHINE Filed May 4, 1940 1 Jaw/r0 MJJ QM I WqATTORNEY.

Oct. 19, 1943. H. J. BRUNK HIGH SPEED BLUE PRINTING MACHINE Filed May 4, 1940 4 Sheets-Sheet 5 JMM SMATTORNEYS.

.Oct. 19, 1943. H. J. BRUNK 2,332,296

HIGH SPEED BLUE PRINTING MACHINE Filed May 4, 1940 4 Sheets-Sheet 4 mvmoz;

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Patented Oct. 19, 1943 HIGH-SPEED BLUEPRINTING MACHINE Harold J. Brunk, Chicago, 111., assignor .to The C. F. Pease Company, a corporation of Delaware Application May 4, 1940, Serial No. 333,415

2 Claims.

My invention relates to improvements in blue print machines and particularly to continuous machines for making blue prints and other prints, in which a sheet of light-sensitive paper is fed through the machine and is printed, developed, washed and dried automatically.

The general object of the invention is to provide a machine of this character which is capable of higher production than those used heretofore, i. e. one which will print faster, dry faster and wash more thoroughly, without sacrificing the important elements of cleamess and permanence in the finished prints but on the contrary will produce prints which are clearer, flatter, and which cost less per square foot than those commercially available in the past.

A contributory object is to provide a machine through which difierent printing papers may be run more rapidly than is otherwise possible.

Another object is to provide a machine which is capable of producing more light for printing purposes and which has more accurate light control to insure proper exposure without changing production speeds.

A further object is to provide developing equipment for paper of this character which makes use of horizontal tank washes which thoroughly wet the paper and allow it to flow easily without tension and by means of which and the free circulation of water in all directions, bleeding is practically eliminated,

An additional object is to provide a machine which enables the operator to regulate the same accurately for variations in tracing densities.

Another object is to provide a machine having a number of drying drums greater than commercial machines in use in the past and so heated that the prints are completely dried in their course through the drums and the paper is smoothed so well that the prints lie smooth and fiat when trimmed. Also, said prints may be so thoroughly dried that they can be run through the machine again immediately if van dykes or blue line prints are desired.

A further object is to provide a machine having simplified heat control which provides an even distribution of the heat for drying, using either gas or electricity in the smallest possible quantities.

An additional object is to provide a machine having centralization of all of the controls where by said machine may be operated conveniently by one man.

Another object is to provide a machine the parts or which are durable and also accessible for cleaning, lubrication and adjustment.

A further object is to provide a machine of this character of attractive design.

Other objects and advantages will be apparent from a consideration of a commercial embodiment of the invention, which is shown in the accompanying drawings.

Fig. 1 is a side elevation of the'machine;

Fig. 2 is a similar elevation partly diagram matic;

Fig. 3 is a front elevation of the first heating drum and part of the driving mechanis; therefor;

Fig. 4 is a side end view thereof;

Fig. 5 is a perspective view'of the machine, viewed mainly from the front, with certain parts removed;

Fig. 6 is an end elevation of a threading device; and

Fig. 7 is a front elevation thereof.

A sheet or sensitized paper, as for example a sheet of blue print paper, is indicated in its travel through the machine by Hi and is unwound from a supply roll il mounted at one end of the machine which may be called the front of the machine. This sheet of paper is guided in the usual manner past a source of light such as a series of arc lamps l2 and passes over or around a number of rolls, to the rear of the machine, as hereinafter described.

The are lamps are connected in circuit to suitable-resistances (not shown) and controlled by a switch l3 conveniently located near the front of the machine for the purpose of cutting said resistances in or out, whereby the intensityof the light emitted by all of said are lamps may be varied simultaneously to regulate the exposure without changing the speed at which the paper travels through the machine, as has been the practice heretofore. The resistances are located in the compartment below the arc lamps and a suitable duct leads therefrom to the drier drums to augment the heat supplied to said drums by gas flames or electrically, as hereinafter described.

After leaving the printing section the paper travels toward the rear of the machine, under or over a number of rolls or idlers l5, [6, ll, l8, I9, 20, 2!, 22 and 23. The first group of rolls l5-l9 are mounted in or near a pan or tray 24 which is supplied with water to provide the initial developing liquid as in the case of blue prints. This developing pan 24, as shown also in Fig. 2, is provided with an outlet pipe 25 leading to a sump 26.

The inclined bottom of this pan also serves another purpose, hereinafter described.

The paper enters this water bath slowly, traveling downwardly a short space only, and then rearwardly, passing under the first two rolls i5, IS, with its sensitized surface in contact with said rolls, after which it travels almost horizontally but slightly upwardly over the roll I! which is in contact with the rear surface thereof and then slightly downwardly under the roll it and then diagonally upwardly over the roll i9. This travel through the water bath in substantially horizontal position prevents both bleeding and distortion of the paper and wets the paper adequately without applying any considerable tension thereto such as develops in some of the vertical washing machines used heretofore.

The next group of rolls 20, Ii, 22, are mounted in or adjacent a second pan 21 which also contains water adapted to provide the usual water wash. This second pan also is provided with a drain pipe which leads to the sump 26', the upper end 2! or inlet end of said pipe being adiustable vertically to vary the water level.

The water for the initial developing operation is supplied in part by suitable pipes 20, 3i and I2, in the form of sprays which maintain the circulation, and the water for the washing operation carried out in the second tray is supplied by a suitable pipe 32. The paper in traveling to and from the various idler rolls i5-22, previously identified, passes over a number of curved rods or so-called bulger rods 34, which allows the paper to adjust itself without distortion, preventing wrinkles.

After passing upwardly over the rear roll 23, the paper passes around the roll and is guided toward the front of the machine through either of two baths, hypo or potash, contained in the pans or trays 4|, 42, respectively. One of these pans is supplied with potash which is the usual fixing solution used with blue prints and the other is supplied with hypo, used with so-called van dykes or thin, transparent prints which, after drying, may be used as negatives.

The path of the paper through the hypo tank 4i is illustrated by longer dashes than those used to indicate the travel of the paper through the second tank. In passing through the first tank the paper passes under suitable rolls 43, 44 which are mounted on adjustable arms 45 so that said rolls may be swung up aboIe the level of the liquid. After leaving the roll 44 the print passes over an adjustable roll 46 and thence diagonally downwardly under roll 41 in a third pan or water tank 40 and thence horizontally to another idler roll 48 at the end of said tank. When it is desired to apply to the paper the liquid potash in the tank 42, the rolls 4! and 44 are elevated above the liquid in the first tank 4i so that the paper passes under the roll 44 in its elevated position and over a roll 50 which dips in the liquid in the tank 42 and applies the same to the under side of the paper, which at this point is traveling face downwardly, and thence under the roll 41 and through the water wash in the tank 48. The mechanism for raising and lowering these various rolls is not described herein as it forms the subject matter of my Patent 2,219,620, issued October 29, 1940, on my application 240,406, filed November 14, 1938.

From the forward end of the water wash in the tank 48, the paper travels under said idler roll 48 and thence upwardly and over two rolls 5|, ii, in inclined position, and past a final water spray I52, to the heating drums. Just above said water spray are a pair of adjustable squeegees I, 54, to remove any surplus water from the paper before it engages said drums. The front heating drum and the various associated parts are shown on a larger scale in Figs. 3 and 4. The lower squeegee 53 and the upper squeegee 54 are mounted on a suitable rocker arm 55 which is pivotally mounted at 56 so that the lower squeegee may press against the rear surface of the paper and the upper squeegee bear against the face thereof. The rocker arm 55 may be adjusted manually by any suitable handle or other device. The water from the spray 52 flows downwardly over the face of the substantially vertical span of paper shown in Fig. 1, and collects in the tank 44, and forms preferably the source of supply of the water in said tank. From the tank 48 the overflow is discharged downwardly through a pipe 61 to the tank 24 below it. The overflow from this lower tank is controlled by a short hinged extension 58 at the end of the pipe 25, which hinged extension is operated by a small lever 09,

as hereinafter explained.

Referring now to the heating drums 60, which are arranged preferably in two horizontal rows at the top of the rear portion of the machine, the upper row comprises in this instance five heating drums whereas the lower row comprises four heating drums although the number may be varied to meet different requirements. The rolls are mounted in staggered relation so that the paper passes substantially half way around each heating drum and up and down in substantially vertical spans to the rear of the machine.

The foremost heating drum III, shown in Figs. 3 and 4, has trunnions ti and 82 by means of which it is mounted in the side frames 83 and 84. roller bearings being preferably provided. The sprocket 68, by which said drum is rotated, is mounted on the outside of the frame with another sprocket 81 mounted between it and saidframe. The chain drive for the sprocket 46 is hereinafter described. On the inside of the same frames,

. above the journals, are mounted a pair of smaller idler sprockets 88, 68. As 'shownin Fig. 3, the plane of said sprockets is positioned between the plane of the main driving sprocket 60 and the adjacent end of the heating drum 60.

As shown in Fig. 1, the paper, after leaving the heating drums 60, passes downwardly around an idler 10 to a driven roll 1i and thence to a loose roll I2 which rests in and is rotated by a pair of driven belts I3, I4 arranged in V-shaped formation in a conventional manner. The roll ll rotates at a rate which will provide a surface speed a little in excess of the speed of travel of the paper, as hereinafter described, so as to tend to maintain the paper under tension. In order to hold the paper in closer frictional contact with said roll, several belts l5, 15 are provided which are mounted on rolls 16, 11 with one of their spans in each case in frictional engagement with the paper. The roll TI is an idler roll but the roll 16 is positively driven, and at a rate which will insure a surface speed of the belt a little in excess of the speed of the travel of the paper. Any suitable mechanical connections may be employed for driving said roll 16, as, for example, a spur gear on its shaft meshing with another spur gear on the shaft of the roll ll, shown in Fig. 2. Thus the paper is engaged on both sides by moving surfaces which tend to maintain it under the desired tension.

As hereinafter described, in the embodiment shown herein, each drum is positively driven by a chain and sprocket connection and hence reliance is not placed on a wind-up roll at the end to pull the paper around the drums.

The means for rotating the drying drums will now be described. A motor 88 (see Fig. 2) is mounted in the base of the machine, and, through an enclosed reduction gearing, drives a chain 8I which in turn drives a pinion 82 near one end of a shaft 83 having a pinion 84 on the other end which drives a chain '85. This chain drives the first heating drum in the series, through the sprocket 88 previously identified in Figs. 4 and 5. The adjacent sprocket 61, on the same axis of rotation, drives a chain 86 which, as shown in Fig. 2, passes down and up alternately over similar sprockets 81, one of which is mounted at the corresponding end of each of the remaining drums. Said driving chain returns in a horizontal span under idler, sprockets 88, 88, as shown in Fig. 2.

As shown also in Fig. 2, the chain drive from the motor also drives an additional chain 88, with its spans arranged substantially horizontally and extending to the rear of the machine where it drives a vertical chain 9I through suitable sprockets, which chain drives an additional chain 92 which rotates the roller 58 mounted in the potash tank 82. The rotation of said roller with respect to the travel of the paper is preferably such as to maintain a puddle of potash between said roll and paper, as described and claimed more fully in Patent 1,852,662, issued April 5, 1932. The chain SI also drives a further chain 93 which rotates the roll II at a surface speed somewhat in excess of that of the paper, as previously stated.

The positive drive for the heating rolls or drums in conjunction with the roll II and the belts I5, for maintaining tension on the paper as it issues from said drums, is one of the important features of the machine, in that these combined rolls and associated parts, provide an ironing action and maintain the paper under sufflcient tension to secure a smooth, dry sheet by the time the end of the paper is wound into the cylindrical roll I2. The paper is fairly wet by the time it reaches the first of the drying rolls and as it passes up and down and around the various heating drums, it gradually shrinks and thus travels at a somewhat slower rate as it leaves the last heating roll, than the rate of travel on entering. -This results in a slight slippage which is distributed over all of the heating drums whereby each of said drums has a certain ironing effect on the paper and the necessary tension is maintained not only as a result of this slippage but also by the roll II and the adjacent belts.

The ironing effect may be obtained also by an arrangement of pulleys and a high friction asbestos driving belt. The tension applied to the belt determines the amount of tension that the paper is subjected to before slippage takes place. With this arrangement the effect is the same as that of locating a friction clutch between the driving sprocket 66 and the first heating drum. Also there is a certain slippage of the paper with respect to said heating drums. With the positive drive previously described, if the paper, in the shrinking process, does not slip readily on the surface of some of the drums, it may break, under certain special conditions.

A threading device is provided, shown in Figs. 3, 4, 6 and 7, which may assume the form of an attachment, although in this case it is built as part of the machine. It comprises a pair of threading chains I88, I88, one of which is mounted near one end of the various heating drums and the other is mounted at the other end, as shown in Fig. 3, so that said chains are spaced apart a distance slightly greater than the length of said drums. These chains pass over the idler sprockets 88, 88, which are arranged in pairs, as shown in Figs. 2 and 4. Thus these chains follow a path which coincides more or less with the path followed by the paper in passing around the heating drums, as will be evident by a comparison of Figs. 1 and 2. These sprockets are supported on suitable stub shafts I8I, mounted adjustably in the adjacent portions of the side frames of the machine. The lower span of each threading chain passes over additional sprockets I82 and I88 (Fig. 2) on each side, one pair of which is mounted on a shaft provided with a crank I84 whereby the sprockets I83 may be rotated by hand, to cause said chains to travel in the same direction as the normal travel of the paper.

As shown in Figs. 6 and 7, each chain is provided at one point in its length with an elongated cotter pin I85 with a short link I88 rotatably mounted thereon. The free ends of said links support opposite ends of a cross bar I8'I surrounded by a length of aluminum tubing I88.

If the paper breaks during the operation of the machine, the attendant stops said machine, and the end of the main sheet, which may be assumed to have passed over one or more but not all of the heating drums at the time the breakage occurred, is wrapped around or otherwise fastened to the cross bar 1. e. to its aluminum housing, and the machine started. At the same time the operator rotates the sprockets I83 by turning the crank, and thus causes the cross bar to follow an up and down and rearward path almost paralleling the path traversed by the paper. At the same time the operator maintains a slight pressure on the paper so as to avoid any slack due to the tendency of the heating drums to feed the paper forwardly, and after the broken end of the paper reaches the rear of the machine it is disconnected from the cross bar and rolled up by hand and placed on the V-shaped supports afforded by the belts l3 and I4, after which the machine continues to operate in the usual manner.

The links I86, which pivotally support the cross bar, permit the latter to deviate slightly from the exact path pursued by the threading chains I88. Thus this arrangement compensates for the discrepancy arising from the slight difierence in the path of travel of said chains, which pass around two small sprockets near the end of each heating drum along a path which projects beyond the periphery of each drum, as compared with the travel of the paper along a circular path, of a radius represented by the radius of each heating drum.

Since these threading chains are normally at rest, the idler sprockets on which they are mounted are not subjected to any wear during the normal operation of the machine and as they are mounted On bearings of much less diameter than the bearings of the heating rolls, they are not only subjected to less friction but may be much smaller than would otherwise be the case and hence may be formed economically by a stamping process.

Referring again to Fig. 2, the arc lamp resistors are mounted in the lower front part of the machine in the compartment H which is connected by piping III to the space between the arc lamps and the curved glass or contact glass H2. Said compartment H0 communicates through a duct H3 with a motor driven blower Ill. The heated air in the vicinity of the contact glass and the arc lamps is drawn downwardly through the said resistance compartment by the blower and is delivered between the drying cylinders, as hereinafter explained. This heated air from the printer thus flows past the resistance coils in th box, the two heated spaces being in series, and the combined heat of both being delivered by the blower which performs the double function of removing the heated air from the point where it is not desired and making use of it where it will reduce the amount of heat otherwise supplied to dry the paper. In a machine which is equipped with a reactance instead of resistance elements for controlling the arc lamps, the air piping system is the same, taking the heat from the printer through the reactance box and then delivering it to the upper, rear part of the machine.

Said heated air in either case is discharged by the blower I ll, rearwardly and upwardly through conduits H5, H6 to a longitudinal duct I" on one side of the machine, which in this case is preferably the right hand side. These ducts have short discharge pipes H8 each directed toward the opposite side of the machine, whereby the heated air is discharged between each pair of vertical spans of paper to blow out the steam which accumulates and thus eliminate steam pockets under the upper row of drying cylinders and over the lower row.

The drums may be heated either electrically or by gas in the conventional manner or in any approved manner.

During the developing operation, when the paper is passing rearwardly in substantially horizontal position through the tank 24, the chemicals washed from the paper tend to sink and to remain at the deep end of the tank and hence are readily drained through the outlet pipe 25 to the sump 28, wherein the heavy chemicals and paper sizing accumulate. Under the old practice these chemicals and sizing adhered in part to the drain piping below the floor whereas with the present arrangement the pipes leading to the sump from both tanks 24 and 21 are above the floor and are easily accessible for cleaning. By manually adiusting the height of the inlet 29, the level of the water in the tank 24 may be varied and, in viewof the tapering bottom wall, the effective length of the horizontal water wash may also be varied, as will be evident. It is also an important feature of the invention that after the paper leaves the developer or first water wash, it is given a second or clear, fresh water wash in the tank 21.

By the use of this equipment the washing is adequate, despite the high rate of speed of the paper through the water washes. The tension on the paper, caused by washing in a vertical position, as in the prior practice, is relieved so that wrinkling and stretching are substantially obviated. The useof the horizontal water washes not only amply wet the paper at high rates of travel, and allow it to float easily without a substantial amount of tension, but the free circulation of water in all directions substantially eliminates bleedlng.

With reference to drying, if the drums are heated by gas, the operator can regulate the total amount of drying heat by means of valves associted with each individual drum. If the machine is heated electrically, the reactors and potentiometer are substituted for the gas control and the operator can regulate the drum temperatures from the operating position, throughout a wide range. The master switch I8 at the front of the machine is used to cut the heating elements in or out at will in the case of either the gas or electric heater model. Furthermore, the operator may carry on the entire operation without leaving the feed table. I

The threading device is claimed in a separate application, Serial No. 496,737, flied July 30, 1943, and the developing features are claimed in my copending application, Serial No. 502,604, flied September 16, 1943.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as covered in the appended claims.

I claim:

1. A machine for drying a sheet of material having a light-sensitized coating thereon comprising a frame, drying drums rotatably mounted thereon, means for driving certain of said drums to draw said sheet to be dried through the machine, a roll over which said sheet passes after leaving said driven drums, means for driving said roll at a surface speed in excess of the speed of said sheet whereby said roll tends to maintain said sheet under tension and to provide an ironing effect, and an endless belt and supporting rollers therefor, one span of said belt being deflected by said roll and by said sheet which is between the two, to cause said span to press said sheet against said roll.

2. In a drying machine, a drying drum, means for withdrawing a sheet of material having a light-sensitized coating thereon from said drum as it passes thereover, said means comprising a roll over which said sheet passes, means for driving said roll at a surface speed in excess of the speed of said sheet, an endless belt and supporting rollers therefor, one span ofsaid belt being deflected by said roll and by said sheet which is between the two, to cause said spanto press said sheet against said roll, and means fit driving one of said rollers at a surface speed in excess of the speed of said sheet whereby said roll and said belt tend to maintain said sheet under tension and to provide an ironing effect.

HAROLD J. BRUN'K. 

